Tacrolimus versus cyclosporine as primary immunosuppression after heart transplantation: systematic review with meta-analyses and trial sequential analyses of randomised trials

Angiopoietin-Like-4, a Potential Target of Tacrolimus, Predicts Earlier Podocyte Injury in Minimal Change Disease

Podocyte injury plays central roles in proteinuria and kidney dysfunction, therefore, identifying specific biomarker to evaluate earlier podocyte injury is highly desirable. Podocyte-secreted angiopoietin-like-4 (Angptl4) mediates proteinuria in different types of podocytopathy. In the present study, we established an experimental minimal change disease (MCD) rat model, induced by adriamycin (ADR) and resulted in definite podocyte injury, to identify the dynamic changes in Angptl4 expression. We also investigated the direct effects of tacrolimus on Angptl4 and podocyte repair. We determined that the glomerular Angptl4 expression was rapidly upregulated and reached a peak earlier than desmin, an injured podocyte marker, in the ADR rats. Furthermore, this upregulation occurred prior to heavy proteinuria and was accompanied by increased urinary Angptl4. We observed that the Angptl4 upregulation occurred only when podocyte was mainly damaged since we didn’t observe little Angptl4 upregulation in MsPGN patients. In addition, we observed the glomerular Angptl4 mainly located in injured podocytes rather than normal podocytes. Moreover, we found that tacrolimus treatment significantly promoted podocyte repair and reduced glomerular and urinary Angptl4 expression at an earlier stage with a significant serum Angptl4 upregulation. And similar results were confirmed in MCD patients. In conclusion, this study represents the first investigation to demonstrate that Angptl4 can predict podocyte injury at earlier stages in MCD and the identification of earlier podocyte injury biomarkers could facilitate the prompt diagnosis and treatment of patients with podocytopathy, as well as determination of the prognosis and treatment efficacy in these diseases.

Advances in the understanding and management of heart transplantation

Cardiac transplantation represents one of the great triumphs in modern medicine and remains the cornerstone in the treatment of advanced heart failure. In this review, we contextualize pivotal developments in our understanding and management of cardiac transplant immunology, histopathology, rejection surveillance, drug development and surgery. We also discuss current limitations in their application and the impact of the left ventricular assist devices in bridging this gap.

Enteric polymer based on pH-responsive aliphatic polycarbonate functionalized with vitamin E to facilitate oral delivery of tacrolimus

To improve the bioavailability of orally administered drugs, we synthesized a pH-sensitive polymer (poly(ethylene glycol)-poly(2-methyl-2-carboxyl-propylene carbonate)-vitamin E, mPEG-PCC-VE) attempting to integrate the advantages of enteric coating and P-glycoprotein (P-gp) inhibition. The aliphatic polycarbonate chain was functionalized with carboxyl groups and vitamin E via postpolymerization modification. Optimized by comparison and central composite design, mPEG113-PCC32-VE4 exhibited low critical micelle concentration of 1.7 × 10(-6) mg/mL and high drug loading ability for tacrolimus (21.2% ± 2.7%, w/w). The pH-responsive profile was demonstrated by pH-dependent swelling and in vitro drug release. Less than 4.0% tacrolimus was released under simulated gastric fluid after 2.5 h, whereas an immediate release was observed under simulated intestinal fluid. The mPEG113-PCC32-VE4 micelles significantly increased the absorption of P-gp substrate tacrolimus in the whole intestine. The oral bioavailability of tacrolimus micelles was 6-fold higher than that of tacrolimus solution in rats. This enteric polymer therefore has the potential to become a useful nanoscale carrier for oral delivery of drugs.

Advantageous effects of immunosuppression with tacrolimus in comparison with cyclosporine A regarding renal function in patients after heart transplantation

BACKGROUND

Nephrotoxicity is a serious adverse effect of calcineurin inhibitor therapy in patients after heart transplantation (HTX).

AIM

In this retrospective registry study, renal function within the first 2 years after HTX in patients receiving de novo calcineurin inhibitor treatment, that is, cyclosporine A (CSA) or tacrolimus (TAC), was analyzed. In a consecutive subgroup analysis, renal function in patients receiving conventional tacrolimus (CTAC) was compared with that of patients receiving extended-release tacrolimus (ETAC).

METHODS

Data from 150 HTX patients at Heidelberg Heart Transplantation Center were retrospectively analyzed. All patients were continuously receiving the primarily applied calcineurin inhibitor during the first 2 years after HTX and received follow-up care according to center practice.

RESULTS

Within the first 2 years after HTX, serum creatinine increased significantly in patients receiving CSA (P<0.0001), whereas in patients receiving TAC, change of serum creatinine was not statistically significant (P=not statistically significant [ns]). McNemar's test detected a significant accumulation of patients with deterioration of renal function in the first half year after HTX among patients receiving CSA (P=0.0004). In patients receiving TAC, no significant accumulation of patients with deterioration of renal function during the first 2 years after HTX was detectable (all P=ns). Direct comparison of patients receiving CTAC versus those receiving ETAC detected no significant differences regarding renal function between patients primarily receiving CTAC or ETAC treatment during study period (all P=ns).

CONCLUSION

CSA is associated with a more pronounced deterioration of renal function, especially in the first 6 months after HTX, in comparison with patients receiving TAC as baseline immunosuppressive therapy.

Effect of immunosuppressive therapy on the serum fatty acids of phospholipids fraction in patients after heart transplantation

BACKGROUND

The effects of tacrolimus (Tac) and cyclosporine (CsA) on lipid profile is well known; however, little is known about the changes in fatty acids (FA) of phosholipids fraction (PL) in heart transplant patients after treatment with these immunosuppressants. This study aimed to investigate the effect of Tac and CsA on serum FA of PL in heart transplant patients.

METHODS

The study included 23 patients after heart transplantation on Tac (n = 14; group II) or CsA (n = 9; group I). Eleven healthy persons served as a control group. Serum FA of PL were extracted, separated on Sep-Pak NH2, methylated, and measured with the use of gas chromatography. Chemstation software was used to analyze the data.

RESULTS

No differences between the studied groups and control were noted for saturated FA, monounsaturated FA, polyunsaturated FA (PUFA), total FA, and PUFA n-6. The mean value of PUFA n-3 was significantly higher in the CsA group compared with the Tac group (P < .015) and control (P < .002) as well as in the Tac group compared with control (P < .001). For individual FA, higher mean concentration, compared with control, was found for C24, C20:2, C20:4, and C22:6 (P < .001 in all cases) and lower for C18:2cis (P < .001 in both groups) and for C18:3 in the Tac group. The mean values of PUFA n-6 to PUFA n-3 ratios were lower than in control (both P < .001).

CONCLUSIONS

Different pattern of FA of PL may indicate the different FA metabolism in heart transplant patients treated by different immunosuppressants. This should be taken into account when FA supplementation in these patients is considered.

Personalized tacrolimus dose requirement by CYP3A5 but not ABCB1 or ACE genotyping in both recipient and donor after pediatric liver transplantation

Tacrolimus (TAC) is the backbone of an immunosuppressive drug used in most solid organ transplant recipients. A single nucleotide polymorphism (SNP) at position 6986G>A in CYP3A5 has been notably involved in the pharmacokinetic variability of TAC. It is hypothesized that CYP3A5 genotyping in patients may provide a guideline for TAC therapeutic regimen. To further evaluate the impact of CYP3A5 variants in donors and recipients, ABCB1 and ACE SNPs in recipients on TAC disposition, clinical and laboratory data were retrospectively reviewed from 90 pediatric patients with liver transplantation and their corresponding donors after 1 year of transplantation. The recipients with CYP3A5 *1/*1 or *1/*3 required more time to achieve TAC therapeutic range during the induction phase, and needed more upward dose during the late induction and the maintained phases, with lower C/D ratio, compared with those with CYP3A5 *3/*3. And donor CYP3A5 genotypes were found to impact on TAC trough concentrations after liver transplantation. No association between ABCB1 or ACE genotypes and TAC disposition post-transplantation was found. These results strongly suggest that CYP3A5 genotyping both in recipient and donor, not ABCB1 or ACE is necessary for establishing a personalized TAC dosage regimen in pediatric liver transplant patients.

Superior rejection profile during the first 24 months after heart transplantation under tacrolimus as baseline immunosuppressive regimen

Background

The use of tacrolimus (TAC) in patients after heart transplantation (HTX) has increased over the last few years.

Aim

In this retrospective study, we evaluated the effects of a TAC (conventional and extended-release TAC)-based immunosuppressive therapy regarding rejection profile in comparison to a cyclosporine A (CSA)-based regimen in patients after HTX.

Methods

The data of 233 patients who underwent HTX at the Heidelberg Heart Transplantation Center from May 1998 until November 2010 were retrospectively analyzed. Primary immunosuppressive therapy was changed from a CSA (n=114) to a TAC (n=119)-based regimen in February 2006 according to center routine. Follow-up period was 2 years post-HTX. Primary endpoint was time to first biopsy-proven rejection requiring therapy. In all patients, routine follow-up at the Heidelberg Heart Transplantation Center was mandatory.

Results

Multivariate risk factor analysis regarding time to first rejection episode showed no statistically significant differences regarding recipient age, donor age, recipient sex, donor sex, sex mismatch, ischemic time, and diagnosis leading to HTX between the two groups (all P= not statistically significant). Time to first biopsy-proven rejection was significantly longer in the TAC group (intention-to-treat analysis, n=233, log-rank test P<0.0001; per-protocol analysis, n=150, log-rank test P=0.0003). In patients who underwent a change of primary immunosuppression (n=49), a significantly longer time to first biopsy-proven rejection was also found in the primary TAC subgroup (log-rank test P=0.0297). Further subgroup analysis in the TAC subgroups showed no statistically significant differences in time to biopsy-proven rejection under extended-release TAC compared to conventional TAC (intention-to-treat analysis, log-rank test P=0.1736).

Conclusion

Our study demonstrated that a TAC-based primary immunosuppressive therapy is superior to a CSA-based immunosuppressive regimen in patients after HTX regarding time to first biopsy-proven rejection.

The calcineurin inhibitor tacrolimus reduces proteinuria in membranous nephropathy accompanied by a decrease in angiopoietin-like-4

Tacrolimus is an anticalcineurinic agent with potent immunosuppressive activity that has recently been shown to have the added benefit of reducing proteinuria in membranous nephropathy (MN) patients. However, its potential mechanisms remain unknown. To reveal the mechanism, rat cohorts were administered tacrolimus or vehicle from days 7 to 28 after the induction of passive Heymann nephritis (PHN). PHN induction resulted in heavy proteinuria and increased expression of desmin, a marker of injured podocytes. We also showed that the glomerular expression of angiopoietin-like-4 (Angptl4) was markedly upregulated in PHN rats and human MN followed by an increase in urine Angptl4 excretion. In addition, increased Angptl4 expression may be related to podocyte injury and proteinuria. Furthermore, upregulated Angptl4 expression primarily colocalized with podocytes rather than endothelial or mesangial cells, indicating that podocytes may be the source of Angptl4, which then gradually migrated to the glomerular basement membrane over time. However, tacrolimus treatment markedly reduced glomerular and urinary Angptl4, accompanied by a reduction in the established proteinuria and the promotion of podocyte repair. Additionally, glomerular immune deposits and circulating IgG levels induced by PHN clearly decreased following tacrolimus treatment. In conclusion, this is the first demonstration that the calcineurin inhibitor tacrolimus can reduce Angptl4 in podocytes accompanied by a decrease in established proteinuria and promotion of podocyte repair in MN.

Immunosuppression in lung transplantation

Lung transplantation can be a life-saving procedure for those with end-stage lung diseases. Unfortunately, long term graft and patient survival are limited by both acute and chronic allograft rejection, with a median survival of just over 6 years. Immunosuppressive regimens are employed to reduce the rate of rejection, and while protocols vary from center to center, conventional maintenance therapy consists of triple drug therapy with a calcineurin inhibitor (cyclosporine or tacrolimus), antiproliferative agents [azathioprine (AZA), mycophenolate, sirolimus (srl), everolimus (evl)], and corticosteroids (CS). Roughly 50% of lung transplant centers also utilize induction therapy, with polyclonal antibody preparations [equine or rabbit anti-thymocyte globulin (ATG)], interleukin 2 receptor antagonists (IL2RAs) (daclizumab or basiliximab), or alemtuzumab. This review summarizes these agents and the data surrounding their use in lung transplantation, as well as additional common and novel therapies in lung transplantation. Despite the progression of the management of lung transplant recipients, they continue to be at high risk of treatment-related complications, and poor graft and patient survival. Randomized clinical trials are needed to allow for the development of better agents, regimens and techniques to address above mentioned issues and reduce morbidity and mortality among lung transplant recipients.

Role of dendritic cells in the context of acute cellular rejection: comparison between tacrolimus- or cyclosporine A-treated heart transplanted recipients

BACKGROUND

In the last years many studies have been designed to predict risk of acute rejection and to adapt the immunosuppressive therapy. The importance of dendritic cells (DCs) in the immune response, especially their role in tolerance is known. Thus, we investigated the influence of tacrolimus (TAC)-based and of cyclosporine A (CsA)-based immunosuppressive therapies on dendritic cells and the incidence of rejection in heart transplant recipients.

METHODS

Groups consisted of 14 CsA treated and 15 TAC treated patients. At different study time points (0, 3 and 6 months after study begin) peripheral blood from the patients was drawn to analyse (1) blood concentration of CsA or TAC (trough value) and (2) percentages of plasmacytoid and myeloid DC (p and mDC) subsets using flow cytometry. Histological rejection grading was performed of endomyocardial biopsies.

RESULTS

TAC treated patients had significantly higher values of pDCs (CsA group 53.9%±13.0%; TAC group 67.5%±8.4%; p<0.05) and significantly lower values of mDCs than CsA treated patients (CsA group 58%±19.0%; TAC group 45.2%±10.7%; p<0.05). In general, HTx patients with rejection grade of ≥2 had significant lower values of pDCs (55.1%±16.2%) compared to patients without rejection (63.6%±10.5%; p<0.05). TAC-treated patients had significantly less rejections CsA-treated patients (CsA group 0.86±0.95; TAC group 0.2±0.4; p<0.05).

CONCLUSIONS

Our results showed that HTx patients with high pDCs had a lower risk for rejection and that TAC-treated patients had higher pDCs values compared to CsA-treated patients. Future studies need to define individual pDC values to predict acute cellular rejection.

CYP3A5 genotypes affect tacrolimus pharmacokinetics and infectious complications in Chinese pediatric liver transplant patients

Little information is available regarding the impact of cytochrome P450 (CYP) 3A5 on the metabolism of TAC in infant LTx. Therefore, the CYP3A5 genotype of Chinese pediatric recipients (intestine) as well as donors (graft liver) was performed for the purpose of establishing an optimal dosage regimen in children. Sixty-four patients were divided according to CYP3A5 genotype (expression of *1 allele: EX and NEX) for each recipient (R) and donor (D), EX-R/EX-D (n = 21), EX-R/NEX-D (n = 8), NEX-R/EX-D (n = 8) and NEX-R/NEX-D (n = 27). Results indicated that initial TAC daily dose requirement was higher among EX-R/EX-D children compared with those who did not express CYP3A5 (0.28 ± 0.10 vs. 0.19 ± 0.08 mg/kg/day, p < 0.01). CYP3A5 expression contributed an overall of 38.35% to its C/D ratios, and graft liver was a key determinant. Additionally, the EX-R/EX-D group showed significantly higher incidence of infectious complications, lower immune response and was an independent risk factor for the development of infections (odds ratio 3.86, p = 0.025). Donor CYP3A5 expression partially explains TAC dose requirement, the effect of CYP3A5 variation may influence clinical outcomes; therefore, monitoring immune response may be important for preventing risks associated with under- and over-immunosuppression.

Heart transplantation in patients with eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)

BACKGROUND

Heart involvement is the leading cause of death of patients with eosinophilic granulomatosis with polyangiitis (EGPA; formerly Churg-Strauss syndrome) and is more frequent in anti-neutrophil cytoplasm antibody (ANCA)-negative patients. Post-transplant outcome has only been reported once.

METHODS

We conducted a retrospective international multicenter study. Patients satisfying the criteria of the American College of Rheumatology and/or revised Chapel Hill Consensus Conference Nomenclature were identified by collaborating vasculitis and transplant specialists, and the help of the Churg-Strauss Syndrome Association.

RESULTS

Nine ANCA(-) patients who received transplants between October 1987 and December 2009 were identified. The vasculitis and cardiomyopathy diagnoses were concomitant for 5 patients and separated by 12 to 288 months for the remaining 4 patients. Despite ongoing immunosuppression, histologic examination of 7 (78%) patients' explanted hearts showed histologic patterns suggestive of active vasculitis. The overall 5-year survival rate was low (57%), but rose to 80% when considering only the 6 patients transplanted during the last decade. After survival lasting 3 to 60 months, 4 (44%) patients died sudden deaths.

CONCLUSIONS

The search for EGPA-related cardiomyopathy is mandatory early in the course of this type of vasculitis. Indeed, prompt treatment with corticosteroids and cyclophosphamide may achieve restore cardiac function. Most patients in this series were undertreated. For patients with refractory EGPA, heart transplantation should be performed, which carries a fair prognosis. No optimal immunosuppressive strategy has yet been identified.

CYP3A4*22 and CYP3A combined genotypes both correlate with tacrolimus disposition in pediatric heart transplant recipients

BACKGROUND

Tacrolimus metabolism depends on CYP3A4 and CYP3A5. We aimed to determine the relationship between the CYP3A4*22 polymorphism and combined CYP3A genotypes with tacrolimus disposition in pediatric heart transplant recipients.

METHODS

Sixty pediatric heart transplant recipients were included. Tacrolimus doses and trough concentrations were collected in the first 14 days post-transplantation. CYP3A phenotypes were defined as extensive (CYP3A5*1 + CYP3A4*1/*1 carriers), intermediate (CYP3A5*3/*3 + CYP3A4*1/*1 carriers) or poor (CYP3A5*3/*3 + CYP3A4*22 carriers) metabolizers.

RESULTS

CYP3A4*22 carriers needed 30% less tacrolimus (p = 0.016) to reach similar target concentrations compared with CYP3A4*1/*1 (n = 56) carriers. Poor CYP3A metabolizers required 17% (p = 0.023) less tacrolimus than intermediate and 48% less (p < 0.0001) than extensive metabolizers. Poor metabolizers showed 18% higher dose-adjusted concentrations than intermediate (p = 0.35) and 193% higher than extensive metabolizers (p < 0.0001).

CONCLUSION

Analysis of CYP3A4*22, either alone or in combination with CYP3A5*3, may help towards individualization of tacrolimus therapy in pediatric heart transplant patients.

Does the calcineurin inhibitor have influence on cytomegalovirus infection in heart transplantation?

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in heart transplant (HTx). Our aim was to analyze the rate of CMV infection in HTx patients receiving treatment with cyclosporine (CsA) or tacrolimus (Tac). Ninety-five patients were randomized to receive either CsA (53.7%) or Tac (46.3%). We performed prophylaxis with valganciclovir in patients with the highest risk of CMV infection. We considered CMV infection as an increased viral load or the presence of CMV in histological samples. We analyzed baseline characteristics, CMV infection, and other complications. Event-free rates were calculated using the Kaplan-Meier method. There were no significant differences in baseline characteristics between both groups. CMV infection was detected in 31.6% of patients (in 66.7% due to asymptomatic replication). The group treated with Tac had a lower rate of CMV infection (15.9% vs. 45.1%, p = 0.002) and longer CMV infection-free survival time (1440 vs. 899 d, p = 0.001). No differences were observed in the complications analyzed in both groups. The independent risk factors for infection identified in the multivariate analysis were treatment with CsA and bacterial infections. This was the first study to demonstrate a lower rate of CMV infection in patients treated with Tac vs. those treated with CsA after HTx.

Immunosuppressive T-cell antibody induction for heart transplant recipients

BACKGROUND

Heart transplantation has become a valuable and well-accepted treatment option for end-stage heart failure. Rejection of the transplanted heart by the recipient's body is a risk to the success of the procedure, and life-long immunosuppression is necessary to avoid this. Clear evidence is required to identify the best, safest and most effective immunosuppressive treatment strategy for heart transplant recipients. To date, there is no consensus on the use of immunosuppressive antibodies against T-cells for induction after heart transplantation.

OBJECTIVES

To review the benefits, harms, feasibility and tolerability of immunosuppressive T-cell antibody induction versus placebo, or no antibody induction, or another kind of antibody induction for heart transplant recipients.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2012), MEDLINE (Ovid) (1946 to November Week 1 2012), EMBASE (Ovid) (1946 to 2012 Week 45), ISI Web of Science (14 November 2012); we also searched two clinical trial registers and checked reference lists in November 2012.

SELECTION CRITERIA

We included all randomised clinical trials (RCTs) assessing immunosuppressive T-cell antibody induction for heart transplant recipients. Within individual trials, we required all participants to receive the same maintenance immunosuppressive therapy.

DATA COLLECTION AND ANALYSIS

Two authors extracted data independently. RevMan analysis was used for statistical analysis of dichotomous data with risk ratio (RR), and of continuous data with mean difference (MD), both with 95% confidence intervals (CI). Methodological components were used to assess risks of systematic errors (bias). Trial sequential analysis was used to assess the risks of random errors (play of chance). We assessed mortality, acute rejection, infection, Cytomegalovirus (CMV) infection, post-transplantation lymphoproliferative disorder, cancer, adverse events, chronic allograft vasculopathy, renal function, hypertension, diabetes mellitus, and hyperlipidaemia.

MAIN RESULTS

In this review, we included 22 RCTs that investigated the use of T-cell antibody induction, with a total of 1427 heart-transplant recipients. All trials were judged to be at a high risk of bias. Five trials, with a total of 606 participants, compared any kind of T-cell antibody induction versus no antibody induction; four trials, with a total of 576 participants, compared interleukin-2 receptor antagonist (IL-2 RA) versus no induction; one trial, with 30 participants, compared monoclonal antibody (other than IL-2 RA) versus no antibody induction; two trials, with a total of 159 participants, compared IL-2 RA versus monoclonal antibody (other than IL-2 RA) induction; four trials, with a total of 185 participants, compared IL-2 RA versus polyclonal antibody induction; seven trials, with a total of 315 participants, compared monoclonal antibody (other than IL-2 RA) versus polyclonal antibody induction; and four trials, with a total of 162 participants, compared polyclonal antibody induction versus another kind, or dose of polyclonal antibodies.No significant differences were found for any of the comparisons for the outcomes of mortality, infection, CMV infection, post-transplantation lymphoproliferative disorder, cancer, adverse events, chronic allograft vasculopathy, renal function, hypertension, diabetes mellitus, or hyperlipidaemia. Acute rejection occurred significantly less frequently when IL-2 RA induction was compared with no induction (93/284 (33%) versus 132/292 (45%); RR 0.73; 95% CI 0.59 to 0.90; I(2) 57%) applying the fixed-effect model. No significant difference was found when the random-effects model was applied (RR 0.73; 95% CI 0.46 to 1.17; I(2) 57%). In addition, acute rejection occurred more often statistically when IL-2 RA induction was compared with polyclonal antibody induction (24/90 (27%) versus 10/95 (11%); RR 2.43; 95% CI 1.01 to 5.86; I(2) 28%). For all of these differences in acute rejection, trial sequential alpha-spending boundaries were not crossed and the required information sizes were not reached when trial sequential analysis was performed, indicating that we cannot exclude random errors.We observed some occasional significant differences in adverse events in some of the comparisons, however definitions of adverse events varied between trials, and numbers of participants and events in these outcomes were too small to allow definitive conclusions to be drawn.

AUTHORS' CONCLUSIONS

This review shows that acute rejection might be reduced by IL-2 RA compared with no induction, and by polyclonal antibody induction compared with IL-2 RA, though trial sequential analyses cannot exclude random errors, and the significance of our observations depended on the statistical model used. Furthermore, this review does not show other clear benefits or harms associated with the use of any kind of T-cell antibody induction compared with no induction, or when one type of T-cell antibody is compared with another type of antibody. The number of trials investigating the use of antibodies against T-cells for induction after heart transplantation is small, and the number of participants and outcomes in these RCTs is limited. Furthermore, the included trials are at a high risk of bias. Hence, more RCTs are needed to assess the benefits and harms of T-cell antibody induction for heart-transplant recipients. Such trials ought to be conducted with low risks of systematic and random error.

A comparison of traditional versus contemporary immunosuppressive regimens in pediatric heart recipients

OBJECTIVES

To assess the differences in rejection and infection complications between the most common contemporary immunosuppression regimen in pediatric heart transplantation (cytolytic induction, tacrolimus based) and classic triple-therapy (cyclosporine based without induction).

STUDY DESIGN

We performed a retrospective, historical-control, observational study comparing outcomes in patients who underwent traditional immunosuppression (control group, n = 64) with those for whom the contemporary protocol was used (n = 39). Episodes of rejection, viremia (cytomegalovirus or Epstein-Barr virus), serious bacterial or fungal infections, anemia or neutropenia requiring treatment in the first year after heart transplantation, and 1-year survival were compared between traditional and contemporary immunosuppression groups.

RESULTS

The 2 groups were similar with respect to baseline demographics. There were no differences in risk of cytomegalovirus, Epstein-Barr virus, or bacterial or fungal infections in the first year post-transplantation. Patients in the contemporary group were more likely to need therapy for anemia (51% vs 14%, P < .001) or neutropenia (10% vs 0%, P = .019). However, more contemporary protocol patients were rejection-free in the first year post-transplantation (63% vs 41%, P = .03). Overall graft survival was similar between groups (P = .15).

CONCLUSIONS

A contemporary immunosuppression regimen using tacrolimus, mycophenolate mofetil, and induction was associated with less rejection in the first year, with no difference in the risk of infection but greater risk of anemia and neutropenia requiring treatment. Long-term follow-up on these patients will evaluate the impact of the immunosuppression regimen on survival.

Tacrolimus versus cyclosporin as primary immunosuppression for lung transplant recipients

BACKGROUND

Lung transplantation is a well-accepted treatment for people with most end-stage lung diseases. Although both tacrolimus and cyclosporin are used as primary immunosuppressive agents in lung transplant recipients, it is unclear which of these drugs is better in reducing rejection and death without causing adverse effects.

OBJECTIVES

To assess the benefits and harms of tacrolimus versus cyclosporin for primary immunosuppression in lung transplant recipients.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 10 April 2013 through contact with the Trials Search Co-ordinator using search terms relevant to this review. We also searched Science Citation Index Expanded and the Transplant Library to 20 April 2013.

SELECTION CRITERIA

We included all randomised controlled trials (RCT) that compared any dose and duration of administration of tacrolimus versus cyclosporin as primary immunosuppressive treatment in lung transplant recipients. Our selection criteria required that all included patients received the same additional immunosuppressive therapy within each study.

DATA COLLECTION AND ANALYSIS

Three authors extracted data. For dichotomous data we used risk ratio (RR) and used mean difference (MD) for continuous data, each with 95% confidence intervals (CI). Methodological components of the included studies were used to assess risk of systematic errors (bias). Trial sequential analysis was used to assess risk of random errors (play of chance).

MAIN RESULTS

We included three studies that enrolled a total of 413 adult patients that compared tacrolimus with microemulsion or oral solution cyclosporin. All studies were found to be at high risk of bias. Tacrolimus seemed to be significantly superior to cyclosporin regarding the incidence of bronchiolitis obliterans syndrome (RR 0.46, 95% CI 0.29 to 0.74), lymphocytic bronchitis score (MD -0.60, 95% CI -1.04 to -0.16), treatment withdrawal (RR 0.27, 95% CI 0.16 to 0.46), and arterial hypertension (RR 0.67, 95% CI 0.50 to 0.89). However, the finding for arterial hypertension was not confirmed when analysed using a random-effects model (RR 0.54, 95% CI 0.17 to 1.73). Furthermore, trial sequential analysis found that none of the meta-analyses reached the required information sizes and cumulative Z-curves did not cross trial sequential monitoring boundaries. Diabetes mellitus occurred more frequently among people in the tacrolimus group compared with the cyclosporin group when the fixed-effect model was applied (RR 4.24, 95% CI 1.58 to 11.40), but no difference was found when the random-effects model was used for analysis (RR 4.43, 95% CI 0.75 to 26.05). Again, trial sequential analysis found that the required information threshold was not reached and cumulative Z-curve did not cross the trial sequential monitoring boundary. No significant difference between treatment groups was observed regarding mortality (RR 1.06, 95% CI 0.75 to 1.49), incidence of acute rejection (RR 0.89, 95% CI 0.77 to 1.03), numbers of infections/100 patient-days (MD -0.15, 95% CI -0.30 to 0.00), cancer (RR 0.21, 95% CI 0.04 to 1.16), kidney dysfunction (RR 1.41, 95% CI 0.93 to 2.14), kidney failure (RR 1.57, 95% CI 0.28 to 8.94), neurotoxicity (RR 7.06, 95% CI 0.37 to 135.19), and hyperlipidaemia (RR 0.60, 95% CI 0.30 to 1.20). Trial sequential analysis showed the required information thresholds were not reached for any of these outcome measures.

AUTHORS' CONCLUSIONS

Tacrolimus may be superior to cyclosporin regarding bronchiolitis obliterans syndrome, lymphocytic bronchitis, treatment withdrawal, and arterial hypertension, but may be inferior regarding development of diabetes. No difference in mortality and acute rejection was observed between patients treated with tacrolimus and cyclosporin. There were few studies comparing tacrolimus and cyclosporin after lung transplantation, and the numbers of patients and events in the included studies were limited. Furthermore, the included studies were deemed to be at high risk of bias. Hence, more RCTs are needed to assess the results of the present review. Such studies ought to be conducted with low risks of systematic errors (bias) and of random errors (play of chance).

Renal complications following lung and heart-lung transplantation

As survival improves after lung and heart-lung transplants, the long term detrimental impact of current management on renal function becomes more apparent as the number of non-renal solid organ transplant recipients on renal transplant waiting lists increases. Progressive chronic kidney disease (CKD) is a significant cause of morbidity and mortality in the transplant population. In this review we discuss the specific problems prior to lung or heart-lung transplant that predispose to CKD, as well as potential renal complications encountered during the peri- and post-transplant period. Significant acute and chronic nephrotoxicity is caused by calcineurin inhibitors (CNI). Mechanisms to decrease CNI exposure exist but have yet to be adopted in routine clinical care. Modifiable risk factors and the current screening and management approach taken at our institution are described. Pediatric nephrologists should be involved from an early stage. Future work will need to focus on identifying more accurate measures of renal function, given the limitations of current glomerular filtration rate estimation equations in a population where nutritional status may rapidly change post transplant. Multicentre studies of CNI minimisation strategies are required to guide future therapy that aims to minimise CKD development and progression in this vulnerable population.

Management of post-transplant diabetes

New onset diabetes mellitus after transplant (NODAT) refers to the development of diabetes post-transplant in previously non-diabetic patients and is associated with increased rates of acute transplant rejection, infection, late cardiovascular events, and decreased survival. NODAT is primarily due to the immunosuppressive drug regimen but the standard predisposing risk factors for diabetes also pertain. NODAT is diagnosed by the standard ADA criteria, once prednisone doses are less than 10 mg per day and in the absence of acute illness. Sulfonylureas, metformin, DPP-4 inhibitors, GLP-1 agonists, and insulin can be used in treatment, but when there is impaired kidney or hepatic function, special precautions are necessary. In addition, those drugs interacting with P450 enzymes require additional consideration because of possible interaction with immunosuppressive drug metabolism.

Some transformations of tacrolimus, an immunosuppressive drug

Transformations of the macrocyclic lactone tacrolimus (1), an important immunosuppressive drug produced by Streptomyces species, are described. These transformation products are primarily of interest as reference substances for drug impurity analyses. Upon action of acid (p-toluenesulfonic acid in toluene), tacrolimus is dehydrated by loss of water from the β-hydroxyketone moiety with partial inversion of configuration at C-8, resulting in formation of 5-deoxy-Δ(5,6)-tacrolimus and 5-deoxy-Δ(5,6)-8-epitacrolimus. The structure of the latter was determined by single-crystal X-ray crystallography. The same products are formed upon action of free radicals (iodine in boiling toluene), along with formation of 8-epitacrolimus. The latter is converted by p-toluenesulfonic acid to 5-deoxy-Δ(5,6)-8-epitacrolimus. Treatment of tacrolimus with weak base (1,5-diazabicyclo[4.3.0]nonene) gives, in addition to 8-epitacrolimus, the open-chain acid corresponding to 5-deoxy-Δ(5,6)-tacrolimus, a rare non-cyclic derivative of tacrolimus. Strong base (t-butoxide) causes pronounced degradation of the molecule. Thermolysis of tacrolimus leads to ring expansion by an apparent [3,3]-sigmatropic rearrangement of the allylic ester moiety with subsequent loss of water from the β-hydroxyketone moiety. ¹H and ¹³C NMR spectra of the obtained compounds, complicated by the presence of amide bond rotamers and ketal moiety tautomers, were assigned by extensive use of 2D NMR techniques.

Effects of immunosuppressants, FK506 and cyclosporin A, on the osteogenic differentiation of rat mesenchymal stem cells

Purpose

The purpose of this study was to investigate the effects of the immunosuppressants FK506 and cyclosporin A (CsA) on the osteogenic differentiation of rat mesenchymal stem cells (MSCs).

Methods

The effect of FK506 and CsA on rat MSCs was assessed in vitro. The MTT assay was used to determine the deleterious effect of immunosuppressants on stem cell proliferation at 1, 3, and 7 days. Alkaline phosphatase (ALP) activity was analyzed on days 3, 7, and 14. Alizarin red S staining was done on day 21 to check mineralization nodule formation. Real-time polymerase chain reaction (RT-PCR) was also performed to detect the expressions of bone tissue-specific genes on days 1 and 7.

Results

Cell proliferation was promoted more in the FK506 groups than the control or CsA groups on days 3 and 7. The FK506 groups showed increased ALP activity compared to the other groups during the experimental period. The ALP activity of the CsA groups did not differ from the control group in any of the assessments. Mineralization nodule formation was most prominent in the FK506 groups at 21 days. RT-PCR results of the FK506 groups showed that several bone-related genes-osteopontin, osteonectin, and type I collagen (Col-I)-were expressed more than the control in the beginning, but the intensity of expression decreased over time. Runx2 and Dlx5 gene expression were up-regulated on day 7. The effects of 50 nM CsA on osteonectin and Col-I were similar to those of the FK506 groups, but in the 500 nM CsA group, most of the genes were less expressed compared to the control.

Conclusions

These results suggest that FK506 enhances the osteoblastic differentiation of rat MSCs. Therefore, FK506 might have a beneficial effect on bone regeneration when immunosuppressants are needed in xenogenic or allogenic stem cell transplantation to treat bone defects.

Nephro and neurotoxicity of calcineurin inhibitors and mechanisms of rejections: A review on tacrolimus and cyclosporin in organ transplantation

CONTEXT

In the meadow of medical sciences substituting a diseased organ with a healthy one from another individual, dead or alive, to allow a human to stay alive could be consider as the most string event. In this article we review the history of transplantation, mechanisms of rejection, nephro-neurotoxicity of tacrolimus and cyclosporin in organ transplantations.

EVIDENCE ACQUISITIONS

Directory of Open Access Journals (DOAJ), Google Scholar, Pubmed (NLM), LISTA (EBSCO) and Web of Science have been searched.

RESULTS

The first reference to the concept of organ transplantation and replacement for therapeutic purposes appears to be to Hua-To (136 to 208 A.D), who replaced diseased organs with healthy ones in patients under analgesia induced with a mixture of Indian hemp. In 1936, the first human renal transplant performed by Voronoy in Russia. The first liver transplant in humans was performed on March 1, 1963 by Starzl in Denver, USA. Medawar was the first to assert that rejection was an immunological response, with the inflammatory reaction due to lymphocyte infiltration. Consequently, rational immunosuppressive therapies could inhibit deleterious T-cell responses in an antigen specific manner.

CONCLUSIONS

Searching related to the history of organ transplantation from mythic to modern times suggests that, to prevent graft rejection, minimize nephro and neuro toxicity monitoring of immunosupressive concentrations could provide an invaluable and essential aid in adjusting dosage to ensure adequate immunosuppression.

Urinary tract infection in renal transplantation

INTRODUCTION

Urinary tract infection (UTI), especially recurrent UTI, is a common problem, occurring in >75% of kidney transplant (KTX) recipients. UTI degrades the health-related quality of life and can impair graft function, potentially reducing graft and patient survival. As urologists are often involved in treating UTI after KTX, previous reports were searched to elucidate underlying causes, risk factors and treatment options, as well as recommendations for prophylaxis of UTI after KTX.

METHODS

Pubmed/Medline was searched and international guidelines and recommendations for prevention and treatment of UTI after KTX were also assessed.

RESULTS

Most studies on UTI after KTX have a small sample, and are descriptive and retrospective. Many transplant- and recipient-related risk factors have been identified. While asymptomatic bacteriuria is often treated, even though some studies advise against it, symptomatic UTI should be treated empirically after collecting urine for microbiological analysis, to avoid the development of transplant pyelonephritis with a high chance of urosepsis. The duration of treatment has not been determined in studies and recommendations refer to the treatment of complicated UTI in the non-transplant population. Prophylaxis has not been the focus of studies either.

CONCLUSION

UTI after KTX is still largely an under-represented field of study, despite many recipients developing UTI after KTX. Prospective studies on this topic are urgently needed.

Endoplasmic reticulum calcium pumps and cancer cell differentiation

The endoplasmic reticulum (ER) is a major intracellular calcium storage pool and a multifunctional organelle that accomplishes several calcium-dependent functions involved in many homeostatic and signaling mechanisms. Calcium is accumulated in the ER by Sarco/Endoplasmic Reticulum Calcium ATPase (SERCA)-type calcium pumps. SERCA activity can determine ER calcium content available for intra-ER functions and for calcium release into the cytosol, and can shape the spatiotemporal characteristics of calcium signals. SERCA function therefore constitutes an important nodal point in the regulation of cellular calcium homeostasis and signaling, and can exert important effects on cell growth, differentiation and survival. In several cell types such as cells of hematopoietic origin, mammary, gastric and colonic epithelium, SERCA2 and SERCA3-type calcium pumps are simultaneously expressed, and SERCA3 expression levels undergo significant changes during cell differentiation, activation or immortalization. In addition, SERCA3 expression is decreased or lost in several tumor types when compared to the corresponding normal tissue. These observations indicate that ER calcium homeostasis is remodeled during cell differentiation, and may present defects due to decreased SERCA3 expression in tumors. Modulation of the state of differentiation of the ER reflected by SERCA3 expression constitutes an interesting new aspect of cell differentiation and tumor biology.

Primary immunosuppression and outcome differences after heart transplantation: tacrolimus versus cyclosporine

BACKGROUND

The superiority of tacrolimus (Tac) as primary immunosuppression for heart transplantation (HT) compared with cyclosporine (CsA) is still under debate. Outcomes of comparison studies are not consistent; the duration of these studies has been limited. The aim of this study was to evaluate long-term outcomes of patients undergoing HT based on primary immunosuppression regime.

METHODS AND RESULTS

We analyzed a single-center registry of all HT patients between 1998 and 2009, comparing outcomes based on primary immunosuppressions (Tac or CsA). Patients who died before starting immunosuppression were excluded. A total of 197 patients entered the study; 103 received Tac and 94 CsA. There were no differences between groups in baseline characteristics, United Network for Organ Sharing status 1A or ventricular assist device use, except for ischemia time (195 ± 50 min in Tac group vs 182 ± 55 min in CsA; P = .08) and days on waiting list (164 ± 155 vs 100 ± 73; P < .001). After mean follow-ups of 4.5 ± 2.3 years in the Tac group and 6.3 ± 4.3 years in the CsA group, there were 19 and 36 deaths, respectively. Kaplan-Meier analysis showed increased survival for the Tac group (log rank P = .04). Tac also was significantly superior to CsA regarding mortality (relative risk 0.55; 95% confidence interval, 0.31-0.98; P = .04).

CONCLUSIONS

In our series the use of tacrolimus resulted in improved long-term survival compared with cyclosporine. At 1-year follow-up, there were no differences in acute rejection episodes or the appearance of vasculopathy.

Age and CYP3A5 genotype affect tacrolimus dosing requirements after transplant in pediatric heart recipients

BACKGROUND

Tacrolimus is one of the commonly used immunosuppressive drugs for pediatric heart transplants. Large variation exists in pharmacokinetics during the direct post-transplant period, resulting in an increased risk of adverse events. Limited data are available on the interaction of age, CYP3A5 and ABCB1 genotype, and disease severity on the variation in disposition and outcome in pediatric heart transplant recipients.

METHOD

We studied the relationship between age and CYP3A5 and ABCB1 genotype and the Pediatric Risk of Mortality (PRISM) score on tacrolimus dose (mg/kg), steady-state trough concentrations, and concentration/dose ratio, as well as rejection and renal function for 14 days after heart transplant in children.

RESULTS

Tacrolimus was administered to 39 children (median age, 6.0 years) after transplant. A correlation was found between the age at the time of transplant and the tacrolimus dosing requirements (r(s) = -0.447, p = 0.004) and the concentration/dose ratio (r(s) = 0.351, p = 0.029). CYP3A5 expressors required median (interquartile range) higher doses of tacrolimus (0.14 [0.09] vs 0.06 [0.04] mg/kg/12 hours, p = 0.001), and had lower concentration/dose ratios (45.34 [44.54] vs 177.78 [145.38] ng/ml per mg/kg/12 hours, p < 0.0001). This relationship was not seen with the ABCB1 genotype. Age and CYP3A5 genotype predicted the tacrolimus dosing requirements as well as the concentration/dose ratio (R(2) = 0.351, p = 0.001 and R(2) = 0.521, p < 0.001). No relationship was found between any of the CYP3A5 or ABCB1 genotypes and the estimated glomerular filtration rate.

CONCLUSION

Younger age and CYP3A5 expressor genotype were independently associated with higher dosing requirements and lower tacrolimus concentration/dose ratios.

Persistent racial disparities in survival after heart transplantation

BACKGROUND

Racial and ethnic disparities are well documented in many areas of health care, but have not been comprehensively evaluated among recipients of heart transplants.

METHODS AND RESULTS

We performed a retrospective cohort study of 39075 adult primary heart transplant recipients from 1987 to 2009 using national data from the United Network of Organ Sharing and compared mortality for nonwhite and white patients using the Cox proportional hazards model. During the study period, 8082 nonwhite and 30 993 white patients underwent heart transplantation. Nonwhite heart transplant recipients increased over time, comprising nearly 30% of transplantations since 2005. Nonwhite recipients had a higher clinical risk profile than white recipients at the time of transplantation, but had significantly higher posttransplantation mortality even after adjustment for baseline risk. Among the nonwhite group, only black recipients had an increased risk of death compared with white recipients after multivariable adjustment for recipient, transplant, and socioeconomic factors (hazard ratio, 1.34; 95% confidence interval, 1.21 to 1.47; P<0.001). Five-year mortality was 35.7% (95% confidence interval, 35.2 to 38.3) among black and 26.5% (95% confidence interval, 26.0 to 27.0) among white recipients. Black patients were more likely to die of graft failure or a cardiovascular cause than white patients, but less likely to die of infection or malignancy. Although mortality decreased over time for all transplant recipients, the disparity in mortality between blacks and whites remained essentially unchanged.

CONCLUSIONS

Black heart transplant recipients have had persistently higher mortality than whites recipients over the past 2 decades, perhaps because of a higher rate of graft failure.

Effect of ABCB1 genotype on pre- and post-cardiac transplantation plasma lipid concentrations

Genetic variation of ATP-binding cassette subfamily B member 1 (ABCB1) which encodes P-glycoprotein (P-gp) has been associated with lipid levels and response to statins. Here, we studied these associations in patients with advanced heart failure who subsequently underwent transplantation. Fasting total cholesterol (TC), low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol and triglycerides (TG) concentrations in 268 adult heart transplant recipients were analysed retrospectively before and at 1 year after transplantation (n = 176). ABCB1 genotyping and haplotyping for C1236T, G2677T/A and C3435T was performed using polymerase chain reaction. Pre-transplant LDL cholesterol was found to be associated with the C3435T genotype and the G2677T/A-C3435T and C1236T-G2677T/A-C3435T haplotypes. T-allele carriers at all loci (n = 77) had higher LDL levels than non-T-allele carriers (n = 24, 3.5 ± 1.2 vs. 2.8 ± 1.2 mmol/L, respectively, p = 0.025). This association remained after adjustment for age, sex, body mass index, statin use and underlying ischaemic heart disease. ABCB1 genotype was not associated with post-transplant lipid parameters. Hypercholesterolaemia (TC >5.7 mmol/L) was more prevalent post-transplant than pre-transplant (51% vs. 30%, respectively) and was likely related to steroid and calcineurin inhibitor use. Muscle-related statin effects were only seen in patients possessing the T-haplotype. In conclusion, an association between ABCB1 haplotype and plasma fasting LDL cholesterol concentration was found in patients with advanced heart failure. This association was not seen 1 year after cardiac transplantation.